Abstract

Solitary waves in photorefractive media have recently been the subject of several theoretical and experimental investigations.¹ Their appearance requires that the nonlinear response be predominantly in phase with the optical excitation so that the diffusion component of the space-charge field is negligible compared to the drift component. A Gaussian beam launched into a photorefractive crystal with diffusion nonlinearity will be deflected in the direction of positive gain, and, depending on the strength of the nonlinearity, the beam will either be focused or defocused. At a critical nonlinearity the beam will maintain its width as it travels.² If such a beam meets the crystal surface so that it is totally internally reflected, one might expect that the beam would be guided along the surface in the same way that a Kerr medium can guide light along a nonlinear interface.³ This paper indicates theoretically the existence of such photorefractively induced waveguides and describes their properties.

© 1995 Optical Society of America